There used to be a day when you could create one generic resume and then blast it to a wide range of jobs you were interested in applying to. Even if you are using a resume service this practice of blasting is generally frowned upon. HR professionals are inundated with resumes and they want to see that applicants have read the ad and are responding directly to it. One-for-all type of resumes are easily spotted and are generally discounted by HR. So work with a resume service to see how you can best tailor yours for each job you are applying to.
Functional format is best for those who are switching their career or have large employment gaps on their resume. In this format, you dont have to list the joining or resigning dates of the previous employments. Functional format will hide your employment gaps or your job switching.
Sometimes its a matter of luck if an employer contacts a job seeker for an interview based on this document. Resume websites provide a more detailed look into a job seekers qualifications and accomplishments. When a job seeker has the necessary qualifications and provides an employer with a link to a resume website the employer will be intrigued because the job applicant is utilizing the latest technology and going over and beyond what is required. If the resume website is done right and includes a resume page an about me page (bio) accomplishments page and images (pictures are worth a thousand words) it will greatly increase the job seekers chances of getting an interview.